Foundry sand rubbing machine



Fb.16,932 E RONCERAY L845J93 FOUNDRY SAND RUBBING MACHINE Filed July 11, 1930 Patented Feb. 16, 1932 UNITED gsiuxrlss' PATENT; oFFIcE EUGENERQNCERAY, or minus,- rnANcE, Ass'IGNoE To socrETE ANONYME Es ETAB- LISSEMENTS rn. BoNvrLLAm'ae E. noNcEnAY, or cHorsY-LE-nor, SEINE, FRANCE FOUNDBY SAND BUBBING MACHINE i Application led July 11, 1930, Serial No. 467,306, and in France February 26, 1980.A

In the normal treatment of foundry sand, the silicious grains of the sand are covered with a iilm of a bonding substance, usually consisting of clay. This operation was formerly performed by a repeated movement of the feet of the foundry men, who executed a sort of pivoting movement upon the surface of their soles, or by a repeated movement of a cylindrical device which was caused to slide upon the sand spread upon a lat plate. Under these conditions the sand can be well covered with vthe said material, but the output of the process is obviously very small.

Attempts have beenmade to imitate such operations by the use of sand-treating machines, but in such apparatus, the real purpose is usually lost sight of, and said maf chines act to only crush and mix the sand.

The modern foundry plants adapted for continuous operation on a large scale'require great quantities of treated sand, especially since it is prevailing tendency to employ only a single quality of sand, instead of a facing sand and a filling sand, it` being desired to economize the former by reason of the insuficient means employed for, its production.

The crushing machines of the pan and muller type usually comprise comparatively narrow mullers of large diameter, and l1 ence their action resembles a rolling and rat a rubbing effect. Certain machines even employ tapered rollers in order to obtain an improved rolling action.

The present invention has for its object a rubbing machine for treating foundry sand, in which the cylindrical mullers have such a length that the line of contact of the roller occupies nearly the whole of the actual ra.- dius of the idisk, in such manner thatethe surface of the mullers will operate a rubbing action by their contact with the disk, on account of the sliding motion due to theA difference in developmentof various points-of them. A

According to another feature of the invention, the stationary knives servin to cut up the fiat cakes of sand are dispose in several groups at diierent points on the surface of rthe said disk and angularly spaced`in each 50 group.

t.comprises a disk 1 which is iotatable on a.V

stationary pivot 2 and rests upon carrying rollers 3; said disk may be driven by a pin-2 ion 4 engaging a toothed ring 4* secured to the disk. To the pivot 2 is keyed a support 5in which are secured horizontal shafts 6-6 'serving aspivots for swinging arms 9--9a in which the muller shafts 8-8a are respectively journalled on said shafts. A

The rubbing-muller 7---7'a which are smooth and of cylindrical shape, are given such a length in the axial direction that the line of contact between the said mullers and the disk 1 shall have the maximum possible length. This line extends upon'the whole of the effective radius of the disk, and'hence all points of the said muller will have the same linear rotary speed,whilst the points of the disk situated on a given radius have linear speeds depending upon their distance from the centre. For this reason, the mullers '7 7'a will slip with reference to the disk 1, and the sand on the disk will thus beX su jected to rubbing stresses.

Sincerthe said mullers are longer than usual, they will preferably have a. reduced diameter, this being substantially equal to their length. Their weight per millimeter of length may vary from 1 to 1.5 kgs. Y

Knives or cutters 10-,10 serves to cut up the ilat cakes of sand before it againproceed under the mullers 7 ,.7; said knivesare not disposed in line as in known machines, in which a sort of .dam will be formed in whose' rear the sand has a tendency to accumulatie, but they 'are mounted in several secured, the rubbing mullers 7-7 being la the surface of the disk, and the knives are angularly spaced in each group.

In the construction herein represented, to the said stationary support 5 are secured two horizontal arms 11, 11a which aresubstantially parallel to the axes of the rollers 7 7a respectively. Each arm 11 or 11a is mountsaid knives are preferably engaged in slots provided in the plates 12, 12a.

Two pairs of such knives are also secured direct to the support 5 in the manner just described. Y

Upon the arms 11 and 11a are also mounted scrapers 13, 13a which serve ,to maintain the mullers in a clean condition. Said scrapers are preferably adjustably mounted, they being provided for instance withA slots 14,

14ea in which are engaged stud bolts 15, 15a

which hold the said scrapers in position.

The machine is also provided with vertically and horizontally adjustable Scrapers for guidingr the sand. `The scraper 16 nearest lthe center is mounted on the support 5 and is inclined from the radius so as to bring the sand which has been supplied near the. center, under the rollers,v7, 7a. An outer scraper 17 mounted at the end of arm 11,

. is inclined in the opposite direction, so that the sand driven into the outside of the disk will be again` brought under the mullers.

- An ejecting scraper 18 is mounted at the end of the other arm 11a and is inclined from the radius in such a manner as to take up they sand at the outer edge ofthe disk and to discharge it from the disk into a recipient or any suitable apparatus adapted for subsequent working operations or for transportation. A handle 19 may be provided onthe spindle 21 carrying the scraper 18 in order to permit an easy adjustment of'theangular position of the latter. "A similar arrangement may beprovided for scraper 17.

The operation is as follows. The sand and bonding material are supplied, by hand lor by mechanical means at the centre of the apparatus, by means .of a spout 22 or the like.

.The scraper 16 acts to direct the said mixture under the mullers 7 and 7 a, and these,

vbeing' actuated by the disk 1, rotate on the axles 8-and 8, also pivotingA on the shafts 6 '6* according to the varylng thickness o the particles of the material to be worked.

Inthis manner the :mullers will` rub the sand, thus forming a' cake which is cut up by the knives 10, 10, the material being then brought under the mullers by the scrapers 17. The sand is subjected to rubbing action, as stated, due to the slipping of the surface ofthe rollers upon the disk 1. The sand, after it has been treated several times by friction under the ,said rollers, is discharged from the disk by the scraper 18'.

The sand can thus be treated in a continuous and entirely automatic manner, provided the raw material is supplied to the machine in suitable proportions. It will be noted that it is an easy matter to incorporate green sand into the old sand, the machine providing for an adequate mixing up ofboth materials.

Obviously, the said invention is not limited to the constructional form herein described and represented, which has been given solely by Way of example.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a foundry sand rubbing machine, the combination of a base plate, a stationary pivot secured to said base plate, a disk rotatable on said pivot, means for supporting and driving said disk, a support on said pivot provided with lateral extensions, a carrier se-4 cured to each of said extensions, at least one j shaft secured on said support, a rocking arm pivoted on said shaft, a muller shaft secured parallel to said carrier, a muller adapted to cooperate with said disk and journalled on to said rocking arm opposite to said shaft and said muller shaft, the axis of said muller being parallel with a radius of said, disk and the generatrix of contact between said muller and said disk extending substantially on thewhole effective length of said radius, several groups of cutters distributed on said support extensions and said carriers for cutting up the cake of sand, a plate on said extensions and carriers to adjustably secure said means, an adjustable scraper on each of the arms for cleaning the lperiphery of said muller, an outer adjustable curved scraper on at least one of said arms and a corresponding central Aone on said support for bringing the sand between the disk and the muller, an outer adjustable curved scraper on at least one of said arms for discharging the worked sand from the disk at a given point thereof, and means for feeding the material to be treated at the central part of the disk. v 2. In a foundry and sand rubbing machine, the combination ofa stationary vertical pivot, a horizontal disk rotatable thereon, suporting means secured to-said pivot and at east one muller rotatably mounted on said supporting means adapted to cooperate with thedisc, the axis of the muller being parallell said radius, and angularly spaced groups ofcutters secured to said supporting means and y angularly spaced in each group for cutting up the cake of sand.

3. In a rubbing machine, adapted to coatV the old silicious grains of foundry sand with a film of a bonding substance, the combination of a horizontal and smooth disc, at least one cylindrical and smooth muller rotatably mountedl about a horizontal axis, means adapted to kimpart a relative rotary motion to said disc and muller about a vertical axis extending through the center of the disc',

means for continuously feeding sand and bonding` substance mixture lat the center of said disc, means for supporting said muller in such a manner` that its whole weight bears upon said mixture sprayed on the disc, and means for cutting up the cake of sand located at the rear ofthe muller, said muller having further such a length that its line of contact with said disc occupies nearly the whole of the radius of the disc.

4. A rubbing machine as claimed in claim 2, wherein said supporting means comprises a shaft situated substantially in the horizontal plane of the muller axis, a swinging arm pivoted at one end on said shaft and carrying at its other end a pin on which is rotatably mounted the muller, the weight of which per millimeter of length varying substantially from 1 to 1.5 kilograms.

5. A foundry sand rubbing machine, comprising a disc and at least onemuller rotatably mounted about a horizontal axis, means adapted to impart a relative rotary motion to said disc and muller about a vertical axis extending through the center of the disc, an-.

gularly spaced groups of cutters, the latter being further angularly spaced in each group, for cutting the cake of sand, and means for supporting said groups of cutters in rigid connection with the supporting means of said muller.

6. A foundry sand rubbing machine, as claimed in claim5, wherein said cutters in each group are clamped in a vertically -adjustable position on said supporting means.

In testimony v vhereof I have signed my name to this specification. l

y ,EUGENE RONOERAY. 

